Clamping wedge



Aug. 29, 1967 c. l. WILLIAMS CLAMPING WEDGE Filed Aug. 26, 1965 Williams I N VEN TOR Chester i. BY cv 26 WITNESS vwcsww United States Patent O 3,338,555 CLAMPING WEDGE Chester I. Williams, 347 Greenbriar SE., Grand Rapids, Mich. 49506 Filed Aug. 26, 1965, Ser. No. 482,788 7 Claims. (Cl. 254-104) This invention provides a wedge for engaging side shoulders on a projecting end of a bolt. The preferred form of the invention has been ydeveloped as a component of a system for securing forms in position preparatory to pouring concrete walls. It is common practice to extend tie members through the space to be occupied by the concreteand secure the opposite form panels to these ties to resist the tremendous pressure of the liquid concrete when it is initially poured. These pressures are distributed over the panels and are collected at the tie points by stiffening beams commonly referred to as studs, and by transverse beams known as walers. The load is transferred to the ties through bolts intersecting the panels, and the bolts, in turn, receive the waler forces through the wedges. The end of a bolt will usually emerge from between -two closely-spaced walers, and the wedge will form a bridge -between the walers. Driving the wedge will result in a tendency to pull the bolt outward between the walers. A spacer can be applied on the bolt at the inside of the walers to produce a clamping action between the spacer and the wedge securing the walers in place with respect to the panels, and thus positioning the form' panels to produce the proper uniform wall thickness.

The bridging function of the wedges makes it vital that the wedges have adequate strength and stiffness in bending. This, of course, can be accomplished by a liberal use of material, 'but the requirements of economy are such that it -becomes necessary to construct a wedge with a minimum of material while maintaining the necessary strength and stiffness. The problem is complicated by the fact that the driving of the wedge may result in positioning the wedge in an almost infinite number of different positions in which the force of the bolt is applied to the wedge and transferred by the wedge to the adjacent walers. The point of application of forces can thus take place at any position over a particular range of movement. The

clamping action of the wedge is generated by the presence of an inclined ramp which is slotted to receive the end of the bolt, with the slot being just wide enough to accept a narrowed portion on the Ibolt which provides shoulders for transferring stresses. The slot communicates with an enlarged opening capable of receiving the full cross section of the bolt so that the wedge can be assembled in position. The wedge construction thus far described is conventional. Applicant has found that it is possibleto form side flanges on the wedge in a cornplementary fashion to the conventional central offset of the wedge (which produces the inclined ramp) in such a fashion that the result is to maintain a relatively constant moment of inertia in bending along the cent-ral portion of the wedge structure where the bending moment is a maximum, and which corresponds to the point of engagement with the bolt. The ramp offset of the wedge, being formed by material extending from the plane of the base, itself provides a large increase in the cross sectional moment of inertia. In the area where this effect is substantial, the flange height can be reduced to present a considerable savings of material without loss of strength or stiffness of the unit. The several features of the invention will be analyzed in further detail through a discussion of the embodiments illustrated in the accompanying drawing. In the drawings:

FIGURE 1 illustrates a perspective view of a fragmentary portion of an erected form structure preparatory to pouring a concrete wall.

3,338,555 Patented Aug. 29, 1967 FIGURE 2 is a perspective view of the wedge shown at opposite ends of the tie system illustrated in FIGURE 1.

FIGURE 3 is a section on the plane 3 3 of FIG URE 2.

FIGURE 4 is a section of the plane 4 4 of FIG- URE 3.

FIGURE 5 is a section on the plane 5 5 of FIG- URE 3.

FIGURE 6 is a plan view of the wedge shown in FIG- URES 1-5.

FIGURE 7 is a modified `form of the invention.

FIGURE 8 is a section of the plane 8 8 of FIG- URE 7.

FIGURE 9 is a section on the plane 9 9 of FIG- URE 7.

The form installation shown in FIGURE 1 includes the opposite panels 10 and 11, the studs 12 and 13, and the walers 14-15' and 16 and 17. The central tie 18 remains submerged in the concrete, and is detachably connected to the bolts 19"and 20. After the concrete has set, the bolts are unscrewed from the tie 18, and the bolts can then be fully disengaged. The structure on both sides of the assembly shown in -FIGURE 1 is substantially identical, and the description of one side will apply equally to the other. Forces transferred along the bolt 20 will be applied to the walers 16- and 17 by the wedge 21 through the engagement of the portions defining the slot 22 with 'the offset formed by the side fiats 23 on the bolt. The hairpin spacer 24 is essentially a clip shaped as the name implies, with one leg traversing a diametral hole in the bolt 20 so that a clamping action can be generated against opposite edges of the walers 16 and 17 between the hairpin 24 and the wedge 21.

The construction of the wedge 21 is best shown in FIG- URES 2-6. The slot 22 is formed in a ramp portion 25 which is offset from the base 26 to -forrn a U-shaped configuration of varying height along the length of the wedge. The inclination of the outside surface 27 (which bears on the offset of the bolt) with respect to the 'bearing surface 28 of the base produces the wedging action responsible for applying clamping forces to the walers. This clamping action is normally generated by applying a hammer to the upper end of the wedge and driving it downward. As the intensity of this action increases, a large force to the left will be applied to the wedge 21 as shown in FIGUR-E 1, which is resisted by forces at the points of contact with the walers. This situation is present in all of the possible positions of the wedge as it is driven `during the tightening procedure.

It is obvious that the combination of the offset formed by the ramp 25 with the base 26 will produce a variation in cross sectional moment of inertia that will be excessive at one end and totally inadequate at the other. To provide complementary strength and stiffness, the side flanges 29 and 30 are provided with low spots 31 and 32 generally opposite the area where the amount of offset forming the ramp 25 is greatest. The height of the flange at 'both sides of 4these low points is gradually increased, which provides `stiffness in the areas along the base which are not adequately stiifened by the presence of the ramp offset alone. Considerable overlap must be provided Where ange stiffness extends into 'the area of substantial rampoffset stiffness in order to prevent the occurrence of a point of weakness at the juncture. For this reason, the low points 32 are considerably displaced along the length of the wedge from the upper end of the ramp offset. Stiffness must be maintained at the upper extremity of the wedge in order -to adequately resist the forces from harnmer blows. i

At the lower end of the wedge, the opening 33 communicates with the slot 22 for receiving the end of the bolt 20 as the wedge is assembled into the position shown in FIGURE 1. The presence of the hole 33 has a tendency to weaken the wedge in a transverse direction, and the end flange 34 is preferably incorporated to prevent the base of the wedge from caving in in response to the large forces applied by the bolt. It is preferable that the flange 34 be formed by a portion which is displaced from the plane of the base bearing surface 28 by an angle 35 less than 90 degrees. This arrangement not only produces a stiffening action, but provides an incline facilitating the movement of the wedge across the wood surface during the installation procedure. It is preferable to incorporate a series of numbers as shown at 36 in FIGURE 6 so that the position ofthe wedge with respect to the bolt can be noted for repeated installations. The holes 37-39 are provided in the base at spaced points along the length of the wedge so that a locking nail can be driven through these holes into the material of the walers to fix the position of the wedge.

Referring to FIGURES 8, 9, and 10, the wedge illustrated in these views is substantially similar to the wedge construction described above. The configuration shown in these latter views is best adapted for cast material, while FIGURES 1 through 6 show a conformation best adapted for sheet metal. The offset ramp 40 of FIGURES 7, 8, and 9 correspond to the ramp 25, and the flanges 41 and 42 extend from the opposite edges of the base 43` in the same manner as the flanges 29 and 30 are associated with the base 26. The end ange 44 is somewhat obscured by the conformation required for casting, but the inclined surface 45 forms a similar function to that of the end ange 34. The slot 46 receives a bolt in the same fashion as previously described.

The particular embodiments of the present invention which have been illustrated and discussed herein are for illustrative purposes only and are not to be considered as a limitation upon the scope of the appended claims.

I claim:

1. A wedge of formed sheet metal for engaging an offset on opposite sides of a projecting member, said wedge comprising:

an elongated base providing a bearing surface, said base having an opening for receiving said projecting member;

at least one side fiange extending along and integral with an edge of said base;

a central ramp offset from said base to provide a U- shaped configuration in cross-section, and also providing a bearing surface on the opposite side of said Wedge from said base bearing surface, said ramp extending beside said flange at an incline with respect to said base, said ramp having a slot communicating with said Opening, the height of said flange being relatively low at points opposite the central portion of said ramp, and relatively high at points opposite the ends of said ramp to maintain a substantially constant moment of inertia in bending along the length of said wedge.

2. A wedge as defined in claim 1, wherein said ramp is disposed between two spaced flanges.

3. A wedge as defined in claim 1, wherein said base has a plurality of holes spaced along the length thereof to receive a locking nail.

4. A wedge as dened in claim 1, wherein said base is tapered to reduced width =at said opening.

5. A wedge as defined in claim 1, wherein said Ibase has an end flange across the end thereof adjacent to said hole, said end ange forming an angle of less than ninety degrees to said -base bearing surface.

6. A wedge as defined in claim 1, wherein the outer surface of said base has a series of numbers in sequence and spaced uniformly along said ramp.

7. A wedge as defined in claim 6i, wherein said numbers are disposed between said ramp and said lange for protection.

References Cited UNITED STATES PATENTS 2,084,417 6/ 1927 Tomkinson 254-104 2,166,444 7/193'9 Kinninger et al. 254-104 2,168,991 8/1939 Hungerford 254-104 OTHELL M. SIMPSON, Primary Examiner. 

1. A WEDGE OF FORMED SHEET METAL FOR ENGAGING AN OFFSET ON OPPOSITE SIDES OF A PROJECTING MEMBER, SAID WEDGE COMPRISING: AN ELONGATED BASE PROVIDING A BEARING SURFACE, SAID BASE HAVING AN OPENING FOR RECEIVING SAID PROJECTING MEMBER; AT LEAST ONE SIDE FLANGE EXTENDING ALONG AND INTEGRAL WITH AN EDGE OF SAID BASE; A CENTRAL RAMP OFFSET FROM SAID BASE TO PROVIDE A USHAPED CONFIGURATION IN CROSS-SECTION, AND ALSO PROVIDING A BEARING SURFACE ON THE OPPOSITE SIDE OF SAID WEDGE FROM SAID BASE BEARING SURFACE, SAID RAMP EXTENDING BESIDE SAID FLANGE AT AN INCLINE WITH RESPECT TO SAID BASE, SAID RAMP HAVING A SLOT COMMUNICATING WITH SAID OPENING, THE HEIGHT OF SAID FLANGE BEING RELATIVELY LOW AT POINT OPPOSITE THE CENTRAL PORTION OF SAID RAMP, AND RELATIVELY HIGH AT POINTS OPPOSITE THE ENDS OF SAID RAMP TO MAINTAIN A SUBSTANTIALLY CONSTANT MOMENT OF INTERTIA IN BENDING ALONG THE LENGTH OF SAID WEDGE. 